Celebrity hacker Guccifer's confession gives us all a lesson in security

The activity of Romanian hacker Guccifer, who has admitted to compromising almost 100 email and social media accounts belonging to U.S. government officials, politicians and other high-profile individuals, is the latest proof that humans are the weakest link in computer security.

Marcel Lehel Lazar, 44, is not a hacker in the technical sense of the word. He's a social engineer: a clever and persistent individual with a lot of patience who a Romanian prosecutor once described as "the obsessive-compulsive type."

By his own admission, Lazar has no programming skills. He didn't find vulnerabilities or write exploits. Instead, he's good at investigating, finding information online and making connections.